Right now I'm using Brave browser which pays BAT (Basic Attention Token) revenue if end users have ads enabled. There definitely are emerging platforms utilizing crypto with the potential to compete with google for ad revenue.
The reason I question the idea of google opposing decentralized apps involves crypto not being necessary for this.
A tech startup could rollout a proprietary, centralized, app that pays users to view ads via paypal. A platform wouldn't need to be decentralized or utilize crypto / token based payment, to compete with google for advertisement based market share.
There are many platforms like: https://www.usertesting.com/
Which harvest user data without utilizing decentralization, blockchain or anything crypto related. One could make the argument that any token based, decentralized, ad competitor to google could do the same job utilizing fiat based payment networks.
There's no real motive in google targeting decentralized apps as all of them could be monetized using apple pay, paypal and other 3rd party apps.
Hard to convince anyone to use different browser or even another search engine like Duckduckgo when they are so used to google. I myself have been using the brave browser for a longtime but since I have my gmail registered to my accounts that had been there long before I discover what google is doing, I'm still using my gmail. Its a slow transition I guess until we can kill the monopoly of Google.
On a personal level, I had switched tons of things over around 5 years ago and my last thing to switch was my e-mail address from a corporate overlord to a better provider. I left it for last because part of me never wanted to switch because I thought it would take too long and not be worth it because of all the legacy accounts I had tied to the e-mail address.
But honestly, despite having 100s of accounts, I was able to migrate them all in about 10-20 hours of work and couldn't be happier to this day about it. My only regret is not having done it sooner.
So if that's any encouragement, I'd say go for it. And it's always better now than later. The longer you wait, the even more entrenched it becomes, not the reverse.